Asymmetric cell division is a phenomenon by which cellular diversity is achieved in the developing organism. Knowledge of the molecular mechanisms by which asymmetric cell division normally occurs is of fundamental importance and relevant to understanding aberrant processes such as tumorigenesis and the origin of developmental defects. Central to these mechanisms in the Drosophila neuroblast is Miranda, a scaffold protein responsible for the asymmetric segregation of cell-fate determinants during mitosis. The structure of Miranda and its complexes with cargo proteins Prospero and Staufen will be investigated utilizing X- ray crystallographic techniques and methodologies. Appropriate quantities of soluble, pure, stable, monodiverse material will be obtained using a rational approach that employs a construct screening strategy. Subsequent crystallization trials will be based on sparse matrix factorial strategies. Use of this "double-screen" approach serves to obtain diffraction quality crystals in an expedient manner so that structure determination may be achieved.